//Example 2.19a
clc;
x1=[1,1,1,1]
x2=[2,2,2,2]
a=1
b=1
a1=0.5
b1=0.5
for n=1:length(x1)
    x3(n)=a*x1(n)+b*x2(n)
end
for n=1:length(x1)
    y1(n)=a1*n*x1(n)+b1
    y2(n)=a1*n*x2(n)+b1
    y3(n)=a1*n*x3(n)+b1
end
for n=1:length(y1)
    z(n)=a*y1(n)+b*y2(n)
end
count=0
for n=1:length(y1)
    if(y3(n)==z(n))
        count=count+1;
     end   
end
if(count==length(y3))
disp('It satisfy the superposition principle');
disp('THE GIVEN SYSTEM IS LINEAR ');
else
    disp('It does not satisfy superposition principle ');
    disp('THE GIVEN SYSTEM IS NON LINEAR');
end